(1) Field of the Invention
The present invention generally relates to earth-working systems, and more particularly, to an apparatus and method for providing real time control of a cutting blade.
(2) Background Information
Relatively sophisticated and powerful geography altering, earth-moving, and/or earth-working machinery have been developed to recontour the topography of large tracts of land, or to otherwise alter the geography of a worksite such as a construction area, a mine, a roadbed, an airport runway, and the like. Machinery of this type (e.g., motor graders and bulldozers) typically include a cutting blade for cutting or sculpting the desired contour as shown in FIG. 1, which is a schematic of a motor grader 50 including a cutting blade 52 (also referred to as a mold board) for contouring a tract of earth.
The advent of computer technology and navigational systems such as satellite, laser, and gyroscope methods has led to the development of various control and/or automated mechanisms for various aspects of geography altering operations. For example U.S. Pat. No. 4,807,131 to Clegg discloses a system wherein an onboard computer receives detection signals from various detection units that are used to control the slope of an earth-engaging blade. U.S. Pat. No. 5,905,968 to Staub, et al., discloses an apparatus and method for controlling a blade on an earth-working machine to preserve a crown on the surface of a road having a sloped grade on either side of the crown. U.S. Pat. No. 6,112,145 to Zachman discloses a blade control system for an earth-working machine for working a surface of earth to a desired shape in which the desired cross slope is maintained when steering the motor grader through a turn (or otherwise articulating the frame).
Despite the advances disclosed in the above cited U.S. Patents, there exists a need for an improved automated control mechanisms for earth-working machines or vehicles, and, in particular, a system and method providing improved and/or expanded blade functionality.
One aspect of the present invention includes a method for real time automated control of the position of a blade on a geography-altering machine. The method includes providing a geography altering machine, including a blade and a computer, the computer having stored therein a reference line and a three-dimensional computer model of a desired topography and providing a user defined offset relative to the reference line. The method further includes determining a blade position in local coordinates, converting the local coordinates to reference line coordinates, the reference line coordinates including a reference station value and a reference offset value, utilizing the reference line coordinates and the user defined offset to calculate blade movement commands, and moving the blade in a direction required by the blade movement commands.
In another aspect, this invention includes a method for controlling in real time the position of a blade on a geography-altering machine. The method includes providing a geography altering machine, including a blade and a computer, the computer having stored therein a reference line and a three dimensional computer model of a desired topography of a work site and providing a user defined offset relative to the reference line. The method further includes determining a blade position in local coordinates. converting the local coordinates to reference line coordinates, the reference line coordinates including a reference station value and a reference offset value, calculating a slope along a segment orthogonal to the reference line at the reference station and extending the slope beyond the user defined offset, which defines a temporary design surface, and moving the blade so that the actual cross slope of the blade is substantially equal to the slope of the temporary design surface.
In yet another aspect, the present invention includes an earth-working machine. The earth-working machine includes: a blade, a blade controller configured for moving the blade, and a computer having stored therein a reference line and a three-dimensional computer model of a desired topography. The computer is configured to prompt a user for a user defined offset relative to a reference line, determine a blade position in local coordinates, convert the local coordinates to reference line coordinates, including reference station and reference offset values, calculate a slope along a segment orthogonal to the reference line at the reference station and extend the slope beyond the user defined offset, defining a temporary design surface, and send blade movement commands to the blade controller for moving the said blade so that the actual cross slope of the blade is substantially equal to the slope of the temporary design surface.
In a further aspect, the present invention includes a method for controlling in real time the position of a blade on a geography-altering machine. The method includes providing a geography-altering machine, including a blade and a computer, the computer having stored therein a reference line for a work site and providing a user defined offset value relative to the reference line. The method further includes determining a blade position in local coordinates, converting the local coordinates to reference line coordinates, the reference line coordinates including a reference station value and a reference offset value, comparing the user defined offset to the reference offset, and moving the blade in a lateral direction relative to the geography altering machine to a position wherein the reference offset is substantially equal to the user defined offset.
In still a further aspect, the present invention includes an earth-working machine. The earth-working machine includes a blade, a blade controller for moving the blade, and a computer having stored therein a reference line and a three dimensional computer model of a desired topography. The computer is configured to prompt a user for a user defined offset relative to a reference line, determine a blade position in local coordinates, convert the local coordinates to reference line coordinates, including reference station and reference offset values, compare the user defined offset to the reference offset, and send blade movement commands to the blade controller.
In yet a further aspect, this invention includes a graphical user interface for displaying in real time the position of a blade on a geography-altering machine relative to a work site. The graphical user interface includes a display selected from the group consisting of: a top plan view including the current position of the machine and the blade, a cross sectional elevational view including a vertical line representing the reference line, and the actual position of the blade taken along a plane parallel to the longitudinal axis of the blade, and numeric indicia representing the station and offset values.